if you have an Android, then you'll need to go to Goodreads on your browser, bc the Goodreads Android app doesn't have a way to get a link to your profile as far as I could tell.

If you have an iPhone there's a little snippet of instructions on the home page of projecttbr.com (it's not visible when you look at the example I linked to)

If you go to the my profile page and the click share button it gives you a link, which ends in the profile id number.